how to block a mobile number call and message receiving in android application development?

I would like to implement an application for block a mobile number for receiving or sending calls and messages.In my application i am entering mobile number at editText box then i am clicking a button for block the mobile number which has entered by the user.

I have implemented an activity class as follows:

public class BlockNumberActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);